Ring barker with pneumatic pressure operated debarking arms



June 16, 1964 R. L. SMITH 3,137,329

RING BARKER WITH PNEUMATIC PRESSURE OPERATED DEBARKING ARMS Filed Oct. 18, 1962 5 Sheets-Sheet 1 20 4'6 INVENTOR- ROBE'RT' L MITH J M M June 16, 1964 sMlTH 7 3,137,329

RING BARKER WITH PNEUMATIC PRESSURE OPERATED DEBARKING ARMS Filed Oct. 18, 1962 5 Sheets-Sheet 2 INVENTOR.

2 ROBERT 1... SMITH June 16, 1964 R. L. SMITH 3,137,329

RING BARKER WITH PNEUMATIC PRESSURE OPERATED DEBARKING ARMS Filed Oct. 18, 1962 5 Sheets-Sheet 3 ROBERT L. SMITH fimwi g June 16, 1964 SMITH 3,137,329

RING BARKER WITH PNEUMATIC PRESSURE OPERATED DEBARKING ARMS 5 Sheets-Sheet 4 Filed Oct. 18, 1962 INVENTOR. R0559)" L. SM/ Th June 16, 1964 R. L. SMITH 3,137,329

RING BARKER WITH PNEUMATIC PRESSURE OPERATED DEBARKING ARMS Filed Oct. 18, 1962 5 Sheets-Sheet 5 INVENTOR. ROBERT L. SMITH wwg g g and 7- -7, respectively, of FIGS. I

Y 3,137,329 I f RING BARKER WETH PNEUMATIC PRESSURE v OPERATED DEBARKING ARMS Robert L. Smith, Seattle, Wash,- assignor to Ederer Corporation, Seattle, Wash, a corporation of Washington p I Filed Oct. 18, U62, Ser. No. 231,458 1 v 21 Claims. (Cl. 144-208) This invention relates to alog barker,.and particularly a log barker of the type in which the log. tobe barked is fed axially through the center of a rotary ring structure,

and in course of said travel has the bark scraped from its periphery by action of debarking tools carried for rotation with the ring structure. The particular debarking tools employed in the present barker comprise scraper toes FIG. -8 is a fragmentary rear elevational view to illustrate onefof asetof thrust bearings for the machines rotating ring structure, employin'gfthe same scale as that of FIG. 3.

v FIG; 8.

FIGJlO is afragmentary longitudinal vertical sectional 'yiew drawngqn a sectionline similar ito that, of FIG. 4 I to illustrate structure which is modified in several respects from the structure shown in1theprecedingviews; and

FIG. 11 is a detail longitudinal vertical sectional view of said--modification drawn on a line shifted circumfen' fixed to the free ends of a set of lever arms fulcrumd to the ringstructure for swing motion toward and from'the rotary axis of the latter about wrist axes paralleling said rotaryaxis and placed at equidistantly spacedintervals about the circumference of a circle having said rotary axis as its center.

For its principal object the invention aims to provide a new and improved ring barker in which pneumatic pressure is employed for forcefully contracting the lever arms in pressing the scraper toes against the surface of the log to be debarked.

As a further important object the invention aims to provide a ring barker in which the pneumatic pressure is applied to the lever arms through the mediumof an annular hose or hoses disposed to occupy a position concentric with the rotary axis of the ring structure, and

I by means vof a wrist pin 31; Ahydraulic jack-32 acts characterized, particularly, in that. the said hose or hoses rotate with the ring structure.

A still further and important object of the invention is to devise a ring barker of the nature described having a perfected control system and one particularly, whichenables the lever arms to be instantly subjected to or relieved from said contracting pressure at thewill of theoperator. g

The invention has the further and ancillary object of providing a ring barker in which the lever arms automatithe rollers rare illustrated in that the same are standard cally move outwardly by centrifugal force upon being T relieved of the contractive influence of the pneumatic pressure, thus precluding the scraper toes fromdigging into the wood of the log should the forward progress of the log be arrested while the same is being conveyed p through the barker.

These and other objects and advantages of "the inven-' tion will appear and be understood in the course of the following description and claims, the'invention: consisting in the-novel construction andin the adaptation and come bination of parts hereinafter described and. claimed.

In the accompanying drawings: FIGURE 1 is a view partly in perspective and partly schematic illustrating :a log barkerconstructed-to embody preferred teachings of the'present'invention.

.FIG. 2 is a fragmentary view thereof drawn to-anenlarged scaleand shown partly in elevation and: partly in transverse vertical section at 2+2 in FIG. 4.

with the section line indicated FIGS. 3 rand-.4 are fragmentary longitudinal 'vertic'al sectional views drawnfonlines 3-3 and 44,--.respec-- tively, ofFIG. 2, with the scaleenlarged from that or FIG. 2. a

FIG. 5 is afragmentary reduced scale elevationalview of the machine FIGSL6 and? are fragmentary longitudinal vertical 'taken' from the end: opposite that of?" 1 sectional views drawn to an enlarged scale onlinesf6'6 entiallyi in a moderate degreefrom the section line. of

FIG. 10.. I I

v Referring to said drawings, the rotary ring structure'of the present invention comprises'inner and outer rings "20 .in part by a rear header '24 secured by 'cap screws 25 to the innerring 20 and'in part by the facing wall 26 of a non-rotary annular housing. This housing surrounds the ring structure and provides rotary journals therefor. De-

. signated generally by 27 lthe housing presents a. leg 28 -(see FIG. 1) which projects laterally from one side. The outer end of this leg' is rooted toa stationary support 30 as a complement tosaid wrist mounting in permitting the housing proper to be adjusted vertically in compensation of thefldifierent diameters of logs-which are to be debarked. These logs;-in their travel through the open cenvter of the described-rotary ring structure, ride over powerdriven step-ribbed rollers. .Neith'er these rollers nor as- .sociated'hold-down' wheels which press .the logs against in the industry as a means of'conveying logs through ring barkers. v j g The leg 28 is made hollow, While not shown'there is housed-in the hollow interior aspur gear whichis driven by anelectric motor.- The split gear drivesthe ring struc- I \tu'rebymeshing an annularring gear 3 8. The ringgear is-secured'by bolts 3 5 td an inturned flange 34' of the outer ring 21-, occupying a position adjacent "to the hous in gs' end'wall 26] and having its facing fiank beve1led,"as .at 33;. Thejtaperedrollers 37 of a; set offour equidistantly spaced thrust bearings engage this'bev elled surface.

vPins 40-about-which the rollersgturnlocate v their axes radiallto the rotary axis of the'ring structure, and :receive' theirgsupportfrom -;a respective one of four, boxes;41 which areyboltably attached to the housing wall 26 in registration with openings through which the rollers project. received at. the rear end of-the latter between the inner ring 20-and a' surrounding ring-shaped retainer 45 se-[ A journal bearing 43 for-the ring "structure. is

curedby bolts 46 to the housings end wall 26.; .For' a purpose which-will-hereinafter appear, a planarsurface 471(.FIG.17) of the retainer 45 closely parallels aifacing planar surface 48' presented by the rear headerl ll Rocker Ishafts' 51;;providethe fulcrums forthe'leverif 1 arms of the present debarker and arecarriedjby the ring structurefor rotation about axes vparalleling jthe rotary :axis of-f the ring structure. The front'header22,;rein-: I forced by aface plate,52,proviclesxa 'journal-forone end of each fshaft, andi the'q inturned llange 34"of= the outer" ring-Z1 providesa journal for'theother end.-jA major lengthofeachfshaftlisexposed tothe hollow vinteri'orof 1 the ,ring .structure, and an ex'tremity' of each shaft pro .jects beyond the front end of the'ringi structure.- {Q The. debia'r kiii 'glever arms 5310f; the presentinvention have-their jhubs55 securely clamped upon; said project;

. jug endsof the shafts. "57 denotes'the}seraperftoes which 3,137,329 Patented June 16, 1964 IG. 9 is. a fragmentary sectional view on line of v are provided upon the free ends of said lever arms. Heelforming lugs 58 extending from the lever hubs at the sides thereof opposite the lever arms act by engagement with stops 60 welded or otherwise secured to the face plates 52 to prescribe an inner limit of swing for the lever arms.

In the hollow interior of the ring structure each rocker shaft 51 has a crank arm 61 keyed thereto so as to 00.-

are of a wrap-around character and are localized upon p 7 the ring by having their open ends clamped to nipples 66 which project frornthe opposite sides of a block The block has a port 68 in its front wall and serves the function of a manifold for supplying and discharging pressure air through said nipples to and from the girding hoses, and to such end is drilled, as at 69, to bring said port into communication with passageways 10 in the nipples. Two fluid-flow lines 54 and 56 connect by a common pipe 78 with said manifold port 68. One leads to the port from a source of pressure air supply 71 (FIG. 1) and is fitted with two valves, namely a control valve 72 and a check valve 73. The other dumps to atmosphere from the port and is fitted with a dump valve 74.

The check valve 73 and the dump valve 74 are each housed in the rear header 24'and are each normally closed, the former by a spring 75 and the latter by a spring 76. Spring 75 workscounter to the pressure of air fed from the source of supply through a passageway 77 to the admission side of the chest in which the valve is housed. The dump valve comprises a shuttle-mounted pressure-balanced spool working between a closed position isolating an admission port 80 from the emission port 81, and an open position bringing said ports into communication. The spring 76 works counter to the force of low-pressure air fed through a pilot passageway 82. Passageway 82 and passageway 77 each connect with a respective one of two circumferential grooves 83 and 84 formed concentric to the rotary axis of the ring structure in the planar face 48 of the header. Registering circumferential grooves 85 and 86 are formed in the planar face 47 of the retainer. Passageways 87 and 88 are drilled in the retainer to connect with the grooves 85 and 86, respectively, and connecting by nipples with the drill-holes are hoses 90 and 91 one to supply high-pressure air from the outlet side of the control valve 72 to the passageway 77, the other to supply air at reduced pressure to the passageway 82. Valve 72 is a 4-way valve controlling delivery of pressure air through saidhose 91 to the passageway 82 as well as through hose 90 to the passageway 77. A third hose 93 leads from a solenoid valve 94 to a manifold passageway formed in the retainer, the solenoid valve being controlled by valve 72 so-as to open and close automtically inconcert with the opening and closing of valve 72, whether such valve 72 is bringing the supply source either into communication with the hose 90 or the hose 91. Each of the hose lines 90, 91

and 93 is fitted with a respective pressure regulating said groove 84'.

4 an opening of the solenoid valve 94 expresses the O-rings against the opposing planar face 48 to establish a seal. Upon a closing of such solenoid valve the pressure air is exhausted back through hose 93 to atmosphere and the 'O-rings responsively move by contraction inwardly to the closed ends of the grooves 96. This closing of the solenoid valve will perforce take place only in concert with an isolation, from the reservoir 71, of the hose or the hose 91, depending upon which of the two had been in communication with the reservoir in consequence of the operation of valve 72. Any pressure air which had been supplied to the pneumatic hoses 65 is held therein by the check valve 73 so that there is of course no need to seal the registering grooves 84-86 against leakage excepting when pressure air is being supplied from the reservoir. 7

Between the reservoir 71 and the two valves 72 and 94 this is provided a lubricator 92 which introduces a minor volume of lubricant to the supplied air. This lubricates the O-rings and the several valves. In the embodiment shown in FIGS. 10 and 11,

tionally like or similar to those of the above-described embodiment. Paralleling planar faces 47 and 48' provided between a bearing retainer 45 and a rear header 24' are conically developed, and the header 24 is adjustable axially toward and'from the inner ring 20', by means'of the bolts 25', so that the spacing between said planar faces can be regulated at will.

The two chests in which valves 73 and 74' are housed are formed in a block which is bolted to the outer face of the header 24, and a cross-over connection 101 is provided within this block between the two chests. The check valve 73' is a ball check closing by a spring 75' against the outlet end of a passageway 102 formed in the block and registering with a passageway 77 is the header leading from a circumferential groove 84 formed in the planar face 48. A passageway (not shown) drilled in the retainer 45' connects hose 90 to a port formed in the planar face 47' in registration with The outlet 103 from the chest in which said ball'check is housed leads directly'by a pipe 56' to the port 68 of the block 67 to which the pneumatic hoses 65' are attached.

The shuttle valve 74' has its spring 76' surrounding a head stem 104 of the valve, and such stem and the valve are center-bored so that pilot air is carried to the base of the valve from a passageway 105 formed in the block 100. Passageway 105 registers with a passageway 82' drilled in the header and leading from a circumferential groove 83' formed in the planar face 48'. A passageway (not shown) drilled in the retainer 45' connects hose 91 to a port formed in the planar face 47' in registration with the groove 83'.

Functioning counterparts 97' of the sealing O-rings 97 are fitted in circumferential grooves 96' cut in the planar face 47'. in positions whereat the rings, when expressed by air pressure outwardly in said grooves, engage the planar face 48' at each of the opposite sides of the circumferential grooves 83 and 84'. The grooves 96. are sectionally of a dove-tail'configuration requiring that the *O-rings be squeezed in order to be expressed, and thus backing off automatically upon being freed of the expressing force of the pressure air. Such pressure air is carried to the grooves through passageways 95' fed from a circumferential groove 106 out in ano'uterfac e of the" retainer and closed by a cover ring 107 to which the hose 93 is attached by a suitable nipple (not shown) Plural sets of said passageways 95 lead 'inw ar'dly from oove 106 at spaced intervals of the circumference;

Distinguished from the indicated weld-connection pr'o' I vided between the inner ring 20 and the .inanifold block 67, the block: 67' and the pneumatic hoses 65' are larranged to be pro-assembled and slipped bodily, as a substantial tire or tires, onto the inner ring 20. The inner I primes of corresponding numbers designate parts which are funcend edge of the block lodges in a notched plate 108 which is welded in place upon the inner ring, and bolts 109 hold the block against displacement axially of the ring.

It is believed that the invention will have been clearly understood from theforegoing detailed description of my now-preferred illustrated embodiments of the invention. Air under pressure fed through supply hose 90 as the manual control valve 72 is openedpasses the check valve 73 and inflates the pressure hoses 65, whereupon the shoes 62 are forced outwardly and act through the crank arms 61 to force the lever arms 53 inwardly. It is desirable that the debarking ends of the lever arms be of such a form that the leading end of a log being conveyed through the open center of the machinesrotating ring structure will, upon reaching the closed lever arms, cause the latter to open in the degree necessary for the log to enter and the debarking process be initiated. Forming 4. A log barker comprising a ring structure journaled for rotation and arranged to receive a log therethrough, power means for rotating thering structure, a plurality of log-barking members located at spaced intervals of the circumference of the ring structure and carried there- 1 by for movement inwardly toward and outwardly fromthe center of rotation, an annular tube inflatable by pneumatic pressure and carried by the" ring structure, a source of pneumatic pressure therefor, operative connections bepress the log-barking'members inwardly, means coneither supplying pressure .air from the source to the inflatable means or dumping pressure air from the ini flatable means, the air dumped being delivered to atmos'-. phere througha normally closed valved port formed in' thering structure. a

the tool ends so as to accomplish this function is no part l of the present invention, being common practice.

Should it be necessary, in course of debarking a log, to arrest the forward progress of the log, the operator, in order to preclude the debarking tools from gouging a groove in the arrested log, is enabled to expand the arms and responsively withdraw'thet'o'ol endsfrom the log by supplying pressure air through the pilot connection to the pilot valve 74, whereupon the spool of the latter valve is shuttled by the pilot air pressure into a position whereat pressure air within the pressure hoses is dumped to atmosphere through port 81. Centrifugal force then causes the debarking levers to swing outwardly away from the log. An operation of the control valve 72 to supply pressure air through hose 90 again brings the debarking levers inwardly against the log when the latter is free to continue its forward progress through the debarking station. V

Changes in the details of construction will suggest themselves and may be resorted to without departing from the spirit of'the invention. It is 'my intention that' no limitations be implied and that the hereto annexed claims played language fairly admits.

What I claim is:

l. A log barker comprising a log-supporting means,.

a ring surrounding the supported log, a'log-barking member, means provided by the ring supportingsaid logbarking member for movement thereof toward and from the supported log in a direction which isgenerally radial thereto, means for effecting relative movement between said barking member and the supported login a dime tion both circumferentially and longitudinally of the log, pneumatic pressure operated means for yieldingly urging the barking member toward the log, a source of air under pressure for said pressure operated means, and means. subject tocontrol of anoperator for either supplying pres-' sure air from said source to the pressure operated means or dumping pressure air from the pressure operated means, said pneumaticmeanscomprising an annular inflatable tubedisposed' concentric tothe, center of .the

ring structure and'carried by the latter in a'position localized with respect to the ring structure.

2. A log barker comprising ring structure arranged to receive a log therethrough, a plurality of lever arms hath be given the broadest interpretation to which the 1em- 1401 ing bark-scraping means on their free ends and fulcrumed, 1

to the ring structure at spaced intervals of the circ'un -f ference'for movement of. said free ends; toward and from the center ofthe ringstructur'e-in a dire'cjtion generally radial thereto, an annular tube inflatablefby pneumatic pressure and carried by the ring structure, a source of pneumatic pressure therefor, and operativeconnections between said inflatable tube and the lever armsacting by inflation of the tube to of thearms inwardly'.

3; Structure accprding to {2; the lions last arm fixedly associated with the lever arm. a

recited comprising a respective crankar'm torieach lever said dump port is opened by supplied'from'the source.

l an ral aunever m xeeiy assoc ted therewit I flatable annular tube carried by the' 'ring' s'truct trolled from a point remote to the ring structure for s. The log barker r claim 4 in which the valve for 6. A log'barker comprising a mounting member, a ring journaled for rotation from the mountingTmember and arranged to receive a log therethrough,,powermeans for rotating the ring, aJplurality of log-barkingmembers "located at; spaced intervals of'the circumference of the" n ring. and carried thereby for movement inwardly toward 1 and outwardly from the center ofrotation'yan annular inflatable tube carried by the ring, a source of pneumatic pressure therefor, controlled means'for supplying pressure'air to and dumping pressure air fromthe tube, and

Operative nections between said inflatable tube and fl 1e-barking embersacting by inflation of the tube to yieldingly'force the barking member i dl 7. The log barker of claim 6 in whichpressure air for the inflation of said tube is fed from the source to the tube through passageways formed in themountingmemher and in the ring registering by annular grooves dis-.

posed concentric with the-ring s axis 'of -rotation and formed in atleast one of two closely' spaced 'facingsun. Y

.faces presented one by said riugjand the other by said 7 *mountingmembenone of said facing surfaces'havin'g an annular grooveat'eachof the oppositesides ofits said registering groove each fitted with a respectivefO-ringn 8. Structure according to claim 7, and means for de livering,. behind theO-rin gs, fromv the source to each of the groovesinwhich said O-Iings are'fitted, a supply of pressure air so as to express the owrings outwardly in their respective groove, means being provid'ed causing. said expresslng' air to' be delivered automatically in concert with a delivery ofpressure air: to-saidregisteringgroove. I

p 9. Structure accordingto claim -7, and'means {foisup plyinga lubricant'to the pressure air fed from said 'so'urce. 10. The log barker. of claim f6 in which pressure. air

ofthe ring'to the inflatable tube traversing. a. check'valve which opensintherdirejctio'ri ot saidfffeed; I j 11. Alog barker comprising a mounting memberiring I structure journaled for rotation from'themounting'rnjern -ber and arrangedto receive .a,logtherethrough;fpower magnate: rotating'the rinstructure, a plurality of lever, armshaving bark-scraping on their "free" ei' diand I fulcrumed from the. ring structure at'spaced intervals of movementiof said free ends towardf- Q and the rotary center. of; "the ring} stru a direction generally 'radialthere t airunder pilot pressure 7 t r tive connection from the tube to the crank arms acting by inflation of the tube to swing the crank arms in a direction responsively causing the free ends of the lever arms tomove inwardl a source of pressure air, and means controlled from a point remote to the ring structure for supplying air under pressure from said source to the tube or exhausting pressure air from the tube to atmosphere, the fulcrums for the lever arms comprising pins journaled for rocker motion adjacent each of their two ends, the respective lever arms being fixed to an end of said pins projecting beyond the related journal, the respective crank arms being fixed to a center portion of said pins lying between the two journals.

' 12. A log barker according to claim 11 in which both the pressure air which is supplied to the tube and the pressure air exhausted from the tube traverse a respective valve carried by the ring structure, said valve for the supply line being a check valve opening with the supplied air, said valve for the exhaust line being a normally closed valve opened by delivery of air under pilot pressure through a pilot line which also leads from the pressure source of supply;

13. A log barker according to claim 12 characterized in that the main supply of pressure air and the pilot supply of pressure air are each delivered to the ring structure through a respective annular groove formed concentric to the axis of rotation of the ring structure in one of two closely spaced paralleling faces of two members one of which is stationary and the other of which row tates with the ring structure, the stationary face having annular sealing grooves cut therein at each of the opposite sides of said air-supply grooves, a respective O-ring fitting each of said sealing grooves, and means for supplying pressure air into said sealing grooves behind the O-rings so as to express the -0-rings against the opposite face of said rotating, member automatically in concert with the delivery of pressure air through either of said airsupply grooves, the sealing grooves being formed so that the -O-rings contract into the grooves in the absence of air pressure behind the 'o-rings.

14. A log barker according to claim 12 characterized in that the main supply of pressure air and the pilot supply of pressure air are each delivered to the ring structure through a respective annular groove formed concentric to the axis of rotation of the ring structure in one of two closely spaced paralleling faces of two members one of which is stationary and the other of which rotates with the ring structure, the stationary face having annular sealing grooves cut therein at each of the opposite sides of said air-supply grooves, a respective O-ring fitting each of said sealing grooves, means for supplying pressure air into said sealing grooves behind the -O-rings so as to'express the O-rings against, the opposite face of said rotating member automatically in concert with the deliveryof pressure air through either of said air-supply grooves, paralleling faces of said two members being conically developed relative to the axis of rotation of the ring structures with the stationary face disposed to the outside, the sealing grooves, sectionally considered,.narrowing toward the open end thereof so that the O-rings retract into the grooves in the absence of air pressure behind the -0-rings.

15. A log'barker according to claim 11 in which the annular tube is a wrap-around tube, the ring structure having a block secured thereto and presenting oppositely directed nipples to which the two ends of the tube are clamped, passageways being provided in the block and the nipples for delivering the pressure air to and discharging same from the tube.

16. Thelog barker ofclairn 15 which means are provided permitting the block and the inflatable tube to.

be pre-assembled and slipped bodily onto the exterior surface of the inner of two paralleling spaced rings com- Qprisingthe ring structure. I, I g t i 17. A log barker according to claim 11, two of said tubes being provided-seating against the ring structure in side-by-side relation, the operative connection from the tube to the crank arms comprising, for each crank arm, arespective single shoe bearing upon the faces of the two hoses opposite the seating faces and attached by a wrist pin to the free end of the crank arm. 7 t,

18. A log barker according to claim 11, the rotary journal for the ring structure comprising an annular hearing, and a plurality of circumferentially spaced thrust bearings each comprising a race bearing against a side face of the ring structure and carried by the mounting member for rotation about an axis radial to the rotary axis of the ring structure.

19. The log barker of claim 11 in which pressure air for the inflation of said tube is fed from the source to the tube through passageways formed in the mounting member and in the ring and connecting by registering annular grooves disposed concentric with the rings axis of rotation and formed in closely adjacent facing surfaces presented one by said ring and the other by the mounting member, said facing surfaces being disposed approximately normal to said rotary axis, said facing ,ing engagement with said opposing face of the ring.

20. A sealing system for use in conjunction with a rotating member and a stationary member presenting closely spaced paralleling faces disposed concentric to g the axis of rotation of the rotating member and characterized in that the rotating member carries a working elej ment activated by pressure air supplied from a stationary source of supply through passageways formed in the stationary member and in the rotating member and registering by a circumferential groove formed in one of said faces, said pressure air delivered to the working element traversing a check valvecarried by the rotating element and opening with the delivered air, valve means associated with the source of pressure air supply for connecting said air-supply groove with or isolating the same from the source, said face of the stationary member presenting circumferential sealing grooves located at each of the opposite sides of said air-supply groove, a respective O-ringfitted in each of said sealing grooves," avalved connection between a source of pressure air supply and each of said sealing grooves acting, when open, to supply pressure air behind the O-rings and responsively express the sameputwardly within said grooves into sealing engagement with the opposing face of the movable member, and means for opening and closing, respectively', the last-named valve automatically in response to the connection of the air-supply groove with, and isolation of said air-supply groove from the air source.

21 A log barker comprising a mounting member, a 'ring structure journaled for rotation from the mounting member and arranged to receive a log therethrough, power means for rotating the ring structure, a plurality of logtbarking members located at spacedtintervals of the circumfere'nce 'ofth'e ring structure and carried thereby for 'movement inwardly toward and outwardly from the center of rotation, an inflatable tubehaving its two ends open, I ablock connected to the ring: structure and formedto present-oppositely directed nipplesto which said open ends of the tube are joined in a manner such that the tube and block collectively produce a substantial tire which, isv adapted, 'to be located 'cojhce'ntric to the rotary axis of ther'ingstructure, a tube-'inflatingsource of pneuw v matic pressure, pressure air supplied from said source against displacement either in an axial or circumferential direction relative to the ring structure.

References Cited in the file of this patent UNITED STATES PATENTS Morgan June 2, 1959 Mullis Oct. 13, 1959 Franked July 19, 1960 Andersson Sept. 11, 1962 

1. A LOG BARKER COMPRISING A LOG-SUPPORTING MEANS, A RING SURROUNDING THE SUPPORTED LOG, A LOG-BARKING MEMBER, MEANS PROVIDED BY THE RING SUPPORTING SAID LOGBARKING MEMBER FOR MOVEMENT THEREOF TOWARD AND FROM THE SUPPORTED LOG IN A DIRECTION WHICH IS GENERALLY RADIAL THERETO, MEANS FOR EFFECTING RELATIVE MOVEMENT BETWEEN SAID BARKING MEMBER AND THE SUPPORTED LOG IN A DIRECTION BOTH CIRCUMFERENTIALLY AND LONGITUDINALLY OF THE LOG, PNEUMATIC PRESSURE OPERATED MEANS FOR YIELDINGLY URGING THE BARKING MEMBER TOWARD THE LOG, A SOURCE OF AIR UNDER PRESSURE FOR SAID PRESSURE OPERATED MEANS, AND MEANS SUBJECT TO CONTROL OF AN OPERATOR FOR EITHER SUPPLYING PRESSURE AIR FROM SAID SOURCE TO THE PRESSURE OPERATED MEANS OR DUMPING PRESSURE AIR FROM THE PRESSURE OPERATED MEANS, SAID PNEUMATIC MEANS COMPRISING AN ANNULAR INFLATABLE TUBE DISPOSED CONCENTRIC TO THE CENTER OF THE 